Sectional pipe for use in conveying abrasive materials



Oct. 20, 1936. N. w. YOUNG 2,057,869

SECTIONAL PIPE FOR USE IN CONVEYING ABRASIYE MATERIALS Fi led Aug 19, 1935 Mrrz's W Ybung Patented Oct. 20, 1936 ATENT OFFICE SECTIONAL PIPE FOR USE IN CONVEYING ABRASIVE MATERIALS Norris W. Young, Mecca, Calif. Application August 19, 1935, Serial No. 36,828

3 Claims.

' This invention relates to the art of conveying abrasive material in a rapidly moving fluid medium and has been especially designed for use in the pneumatic conveyance of concrete.

5: As is well known to those familiar with the art any conduit which is used for the conveyance of abrasivematerial is subjected to excessive wear along the particular surface of the conduit with which the material is thrown into contact or along which the material normally travels, while the remaining wall surface of the conduit is subjected to no abrasive action and will last indefinitely. This is particularly true in the case of bends or other fittings in which the material isdiverted from its course of travel and through such diverting action is effective to continually bombard the wall surface of the bend along the long radius thereof while the wall surface along the short radius. is subjected to no abrasive action whatever. This condition is also present in the caseof a horizontal pipe which isused to convey aheavy abrasive material having a specific gravity such that it rides along the bottom of the pipe producing a scouring action thereon. In other words, underthese circumstances a certain portion of the abrasive material rides along the bottom of the conduit and subjects this portion thereof to excessive wear while the upper portion of the conduit which may be engaged by no material at all or at most by the fluid medium, is subjected to norwear whatever.

It is a primary object of this invention to materially reduce the maintenance expense in a conduit of the general character referred to above 5 by providing a pipe or conduit of sectional construction in which the surface or surfaces thereof, subjected to excessive wear, can be removed and replaced from time to time at a minimum cost. In line with the foregoing object'my invention 40 contemplates the provision of a pipe or conduit member having a body piece provided at its ends withmeans for connecting the same to adjoining sections and formed with a cut-away? or open intermediate portion over which cover means formed of a wear resistant material may be mounted and rigidly secured to the body portion.

It is a further noteworthy feature of this in.- vention that the wear receiving means above referred to are made in the nature of relatively narrow arcuate blocks so that only those particular regions subjected to excessive wear need be replaced when the pipe or conduit is broken down or dismantled for inspection. .This type of v construction has a further advantage in that the blocks are-comparatively light'in weight, particularly with respect to the pipe section itself, and can, therefore, be removed and replaced with little effort, thereby effecting a material saving in time and labor costs.

It is a further important feature of this invention that packing means are provided between the removable cover means and the body portion so that a pressure-tight condition is established in the conduit as soon as the blocks are installed. A still further feature of the invention is that the 10 wear receiving blocks can be made relatively thick and formed or surfaced with metal having a much greater resistance to wear than the metal which must be employed in the construction of the body section or of ordinary pipe. way I am able to greatly increase the life of the pipe section itself. For example, in operations where a conventional extra heavy steel pipe bend will be worn through in twelve hours, sectional pipe of the type contemplated herein, has been used for as long as fifteen days before it is necessary to replace any of the blocks.

In order to obtain the maximum strength in the construction of the body piece, I find it desirable to form the wear receiving arcuate blocks or wear receiving means on an are slightly less than degrees and since this would normally leave a small segment of surface on the body portion subjected to abrasive action along a bend, for example, it becomes a further object of this invention to provide removable strips which may extend down to or below the diametral plane of the conduit which lies along the direction of travel of the material therein, such strip being adapted to receive the wear along the upper side 35 portions of the body section and also being made so that it can readily be removed and replaced.

The details in a preferred form of my invention, together with other objects attending its production, will be best understood from the fol- 40 lowing description of the accompanying drawing which is chosen for illustrative purposes only, and in which Fig. l is a diagrammatic elevation with parts in section illustrating the manner in which one a preferred form of my invention may be employed in connection with a pneumatic gun such as is used in lining an underground tunnel with concrete; 50

Fig. 2 is an enlarged fragmentary elevation with parts broken away illustrating a preferred form of construction contemplated by this invention; and

Fig. 3 is a sectional elevation shown in offset 55 In this 15 planes and taken along the general line indicated at 33 in Fig. 2.

As has been previously pointed out, my invention was developed especially for use in connection with the so-called cement gun equipment which is used for the pneumatic conveyance of concrete and for this reason I have illustrated and will describe the invention in connection with this particular type of equipment although it will be apparent to those familiar with the art that numerous other applications and adaptations may be made of the principles involved and that the invention is not in any way limited to the particular example given herein.v

Referring to Fig. 1 which diagrammatically illustrates the equipment used for lining underground tunnels, reference numeral it indicates a tunnel, a portion of which is provided with a form l2 which is shown as being placed a substantial distance away from the wall of the tunnel and above or behind which concrete is adapted to be projected with considerable force through the medium of the cement gun equipment diagrammatically indicated at l3.

The cement gun asis well known to those familiar with the art comprises a housing or box member l4, into which cement or concrete is adapted to be fed from any suitable source through a hopper IS. A large volume of compressed air under substantial pressure is delivered into this box or chamber through conduit means generally indicated by reference numeral l6, and the concrete is driven from the box or housing through an outlet if, by the compressed air being carried along with the air at a very high velocity and with a tremendous force.

The conduit whereby the concrete together with'its conveying meolium is conducted to the source of application is generally indicated by reference numeral l9 and since it is rarely possible to have a system of this character in which the outlet connection I! from the gun is ona straight line with the point of application, it is necessary to provide the conduit IS with bend fittings, in the case a rigid pipe is used, or to bend the conduit itself in the event a flexible hose is used. At any point where a bend occurs in a conduit/of this character the bombardment of the wall along the long radius of the bend by the abrasive material in the conduit soon wears away the material along this surface requiring the replacement of the complete fitting, in the case of pipe or the replacement of the entire hose in the case this type of conduit is used.

Referring back to Fig. 1, the conduit I9 is shown as being comprised of bend fittings 2| and 22 interconnected by a straight pipe section 23, the bend fitting 22 having a nozzle 24 secured to its end and extending behind the form I2. As has been previously pointed out it is a primary object of this invention to provide a pipe or conduit section of the class described which is formed so that the surface thereof which receives the wear from the abrasive material can be removed and replaced. In the case of a bend fitting of the type indicated at 2! or 22 it is apparent that the wear will take place along the wall which lies on the long radius of the bend. In other'words, the wall portion of the pipe which is nearest the center of curvature of the bend or which lies along the short radius of the bend will be subjected to little or no wear while that portion of the pipe wall which lies farthest from the center of curvature of the bend will receive the direct bombarding action of the abrasive material as it is being turned from its course of travel. In the case of a bent or curved pipe therefore my invention contemplates the provision of removable wear receiving means which are positioned so as to lie along the long radius of the bend or more specifically to provide an outer wall section which is removably or detachably secured to the inner wall section. For the purpose of description herein, I have designated the wall surface nearest the center of curvature as the inner surface indicated at i in Fig. 1

and the wall portion farthest from the center of curvature of the bend as the outer wall portion and have designated the same by the letter 0.

Referring now to Figs. 2 and 3 for more detailed description of a sectional pipe fitting of the type indicated at 22, it will be observed that the fitting 22 consists of what I may term a body piece generally indicated by reference numeral 30. The ends of this body piece 30 are of annular or tubular construction so as to provide end connections indicated by reference numeral 3| which may be threaded or as shown'may be provided with connecting flanges 32. Between the end connections 3| the body piece has an intermediate portion of arcuate or segmental cross section so as to form what may be thought of as a cut-away section intermediate the ends of the pipe thereby leaving an elongated opening in the wall of the body piece, such opening being defined by edges 33 and 33' on the intermediate portion of the body piece.

The edges 33 and 33' are shown as being recessed on their inner surfaces as indicated at 34 and 34' such recesses containing wear receiving strips 35 and 35' which are held in place in any suitable manner such as by means of screw bolts 36..

' Reference numerals 31 and'3'l indicate longitudinal flanges which are formed along the upper edges of the intermediate portion on the body piece, such flanges being associated with upwardly projecting wall sections indicated at 38 and 38'.

Mounted within the wall sections 38 and 38 and supported upon the upper edges of the cutaway intermediate portions and on the wear receiving strips 35 and 35', in the event'these strips are used, are packing strips generally indicated by reference numerals 40 and 40". These packing strips extend along the entire length of the intermediate portion above referred to and are designed to form a pressure tight seal between the body portion and the wear receiving means which is detachably secured thereto.

In this preferred embodiment of my invention the wear receiving means comprises a plurality of arcuate blocks 4!, the edges 42 of which are adapted to rest upon the packing 40. These blocks are preferably of relatively thick cross section and are shown as being provided with raised ribs 43 on their outer surfaces, such ribs forming guides for clamping yokes or saddles 45 which are detachably secured to the body piece through the medium of bolts 46 extending through bosses 41 formed on the flanges 3! and 31'. The yokes or saddles are shown as being U -shaped in cross sections so as to receive a packing member 50 which extends overthe adjacent ends of the successive blocks and is pressed downwardly into any gap which may be left therebetween.

It will be observed that the wear receiving blocks 4! and the wear receiving strips 35 and 35' are shown as being shaped so that they co-operate with the arcuate section in the body piece to form a longitudinal passage of circular cross section which extends throughout the entire length of the pipe. In the particular embodiment chosen for purposes of illustration the body piece is shown as being provided with reinforcing ribs or flanges indicated by reference numerals 50' and 5|.

It will be apparent from the foregoing description that the sectional type of conduit contemplated by this invention provides a construction in which that portion or those portions of the pipe which receive the greatest wear can be removed as the wear becomes excessive and it is to be understood that while I have described my invention with particular reference to a curved or bent fitting, that this construction may be used on various other types of fittings and on straight pipes, the removable wear receiving section or sections of the conduit always being placed in a position where it is subject to the wear abrasive action of the material passing through the conduit. It is emphasized, therefore, that while I have herein described and illustrated one preferred embodiment of the invention and have described the same in connection with one preferred application thereof, that the invention is not limited to the precise construction described above, but includes within its scope whatever changes fairly come within the spirit of the appended claims.

I claim as my invention:

1. A sectional pipe comprising: a body piece having annular end connections and an intermediate open portion formed by a wall of arcuate cross section; a plurality of arcuate blocks mounted on the edges of said wall section and co-operating therewith to close said open portion and form a continuous passage through said pipe said blocks constituting the sole closure wall of said open portion; and detachable means for clamping each of said blocks onto said body piece.

2. A sectional pipe comprising: a body piece having annular end connections and an intermediate wall portion of arcuate cross section, saidintermediate wall portion being formed with longitudinal recesses along its edges; wear receiving strips detachably mounted in said recesses; and wear receiving cover means detachably mounted on the edges of said intermediate wall portion, said cover means extending between said edges to form a continuous passage through said pipe, said strips and said cover means being shaped so as to co-operate with the wall of said intermediate portion to form a passage of substantially circular cross section.

3. A sectional pipe comprising: a body piece having annular end connections and an intermediate wall portion of arcuate cross section; packing strips on the edges of said intermediate wall portion; a plurality of arcuate cover blocks having recessed edges engaging said packing strips; arcuate packing members mounted over the edges of adjacent cover blocks, yoke members mounted over said arcuate packing members; and bolts mounted on said body piece and engaging said yokes for clamping said blocks and said packing strips into pressure fitting engagement with the edges of said intermediate wall portion.

NORRIS W. YOUNG. 

